Install Mac - Os On External Drive

Hold the Option (Alt) key while pressing the power button.

If you want to install macOS on an external drive using another Mac: install mac os on external drive

You need the installation files for the version of macOS you want to run. Hold the Option (Alt) key while pressing the power button

Select the of your external disk from the sidebar. Click Erase and use the following settings: Name: macOS External (or whatever you like) install mac os on external drive